The magnetosphere as a sufficient source for upstream ions on November 1, 1984

The source of energetic particles in two upstream events which occurred during the great magnetospheric compression of November 1, 1984 were investigated. Ten tests, which could distinguish between the Fermi and the leakage sources for upstream diffuse ion events, were applied to simultaneous magnetospheric, magnetosheath, and upstream energetic particle observations obtained during the November-1 upstream events by several spacecraft. Results showed that magnetospheric leakage satisfactorily explains these observations, while in situ Fermi acceleration does not. It is concluded that, during these two events, magnetospheric leakage was a sufficient source for upstream particles.